New spill at Fukushima nuke plant

Hideyuki Ban, secretary general of the nuclear safety group Citizen's Nuclear Information Center, speaks to a gathering of international reporters. He says the overflow of radioactive water at the Fukushima Daiichi plant appears to be a consequence of poor communication and monitoring. Plant operator Tokyo Electric Power apologized for the 100-gallon release.
Morgan Lee

Hideyuki Ban, secretary general of the nuclear safety group Citizen's Nuclear Information Center, speaks to a gathering of international reporters. He says the overflow of radioactive water at the Fukushima Daiichi plant appears to be a consequence of poor communication and monitoring. Plant operator Tokyo Electric Power apologized for the 100-gallon release.

TOKYO  Irradiated water overflowed from a storage tank at the Fukushima Daiichi nuclear plant, adding to concerns about management of a growing stockpile of contaminated water at the oceanside site.

Tokyo Electric Power crews were transferring rainwater that had collected at the base of a storage tank when the estimated 115-gallon leak occurred, said Masayuki Ono, an official at the utility’s plant siting department, on Thursday. The tank was already partially filled with water that had been used to cool nuclear fuel in the station’s reactors.

Tepco is grappling with how to safely store groundwater that has seeped into the wrecked reactors, mixing with cooling water that has been in contact with exposed nuclear fuel. The company has been filling tanks at a rate of 400 metric tons a day -- equal to roughly 106,000 gallons.

The water may have overflowed because the 450-ton-capacity tank had been built on a slope and was at a slight tilt, Ono said. Tepco said in the statement that it can’t rule out the possibility that some of the water flowed to the sea.

Hideyuki Ban, of nuclear safety group Citizen's Nuclear Information Center, said the tanks are typically equipped with a water-level gauge on one side. That gauge would have been ineffective with a tank located on a slope, where the water level is uneven.

"They didn't realize that tank was almost full," Ban told a gathering of international journalists in Tokyo. "This was not communicated properly to the workers."

He cited the spill as evidence new evidence that "Tepco does not have the necessary experience or the structures in place to manage" the plant.

Japan's devastating March 2011 earthquake and tsunami knocked out power and backup generators at the four-reactor facility, cutting off core cooling systems and leading to the meltdown.

A 300-metric-ton water leak from another holding tank was reported by Tepco in August, and has been traced to a seal. The problem is still being diagnosed.

“There are long-term issues that we need to solve and respond to firmly,” Ono of Tepco told a press conference. The new spill was discovered on Wednesday.

The Japanese government has stepped into the Fukushima cleanup to fund a frozen earth retaining wall designed to prevent ground water at the plant from seeping into the ocean, as well as assistance in the eventual processing of irradiated water.

Japan's 50 nuclear reactors are all currently offline, as the Nuclear Regulatory Agency prepares to evaluate restart applications and the government develops a more comprehensive energy supply strategy.

Reiji Takeishi, an energy sector expert at Tokyo International University, expects the agency to eventually clear many of Japan's more recently built reactors for operation, although various plant configurations are still under review.

U-T reporter Morgan Lee is visiting New York, Japan and China through a fellowship with the East-West Center, established by the U.S. Congress to promote better understanding among the peoples of the U.S., Asia and the Pacific.